This is the point of White's plan. The rook becomes active, the knight can go to d3, and we have a strange position on the board with White's central pawns still on their initial squares.
11... a7a5 Preparing Na6-b4 or maybe a5-a4. This highlights a small problem with the bishop on a3. 12. f3e1 Ding chooses an interesting plan, more or less typical of the English Opening, although it looks a bit funny: to play f2-f4 without moving any of the central pawns. 12... f8e8  13. f2f4  13... e5f4 The sharpest continuation.